Fix timeout usage and document some stuff

docker/dev_env/Dockerfile

@@ -1,11 +1,22 @@
 FROM docker.io/library/alpine:latest
 
+# Dependency explanations
+# - git: required by some python package; contributors should use git on their host
+# - coreutils: required for timeout (maybe other utils too) because busybox's doesn't match our usage
+# - perl: used in linting
+# - bash: used for scripts
+# - curl: used by scripts
+# - python3: self-explanatory
+# - pipx: used to install pipenv in the entrypoint, we can remove this after switching fully to pdm
+# - docker*: used to interact with host docker socket
+# - nodejs-current: self-explanatory
+# - npm: required by pre-commit environment to be explicitly installed along with node
+# - just: command runner
 RUN apk add --update --no-cache \
   git \
+  coreutils \
   perl \
   bash \
-  openssh \
-  gnupg \
   curl \
   python3 \
   pipx \
@@ -20,6 +31,8 @@ RUN apk add --update --no-cache \
   addgroup opener docker; \
   corepack enable;
 
+# pipenv, pnpm, and pdm are installed in the entrypoint
+
 COPY entrypoint.sh /entrypoint.sh
 
 WORKDIR /ov

docker/dev_env/entrypoint.sh

@@ -1,5 +1,7 @@
 #! /usr/bin/env bash
 
+set -e
+
 if [ "$(whoami)" != "opener" ]; then
   printf "Do not run this container with the root user! Use the 'run.sh' script or pass --user to docker run.\n"
   exit 1

docker/dev_env/run.sh

@@ -16,16 +16,20 @@ run_args=(
   --env "TERM=xterm-256color"
   --user "$UID:$host_docker_gid"
   --network host
+  # Bind the repo to the same exact location inside the container so that pre-commit
+  # and others don't get confused about where files are supposed to be
   --mount "type=bind,source=$OPENVERSE_PROJECT,target=$OPENVERSE_PROJECT"
+  # Save the home directory of the container so we can reuse it each time
   --mount "type=volume,src=openverse-dev-env,target=$opener_home"
+  # Expose the host's docker socket to the container so the container can run docker/compose etc
   -v /var/run/docker.sock:/var/run/docker.sock
 )
 
 if [ -t 0 ]; then
   run_args+=(-t)
 fi
 
-# Git commit can be mapped, but you won't be able to sign commits inside the
+# Git config can be mapped, but you won't be able to sign commits inside the
 # container. Use your host `git` in that case, please!
 for git_config in /etc/gitconfig "$HOME"/.gitconfig "$XDG_CONFIG_HOME"/git; do
   if [ -a "$git_config" ]; then
@@ -38,6 +42,7 @@ done
 
 host_pnpm_store="$(pnpm store path 2>/dev/null || echo)"
 
+# Share the pnpm cache with the container, if it's available locally
 if [ "$host_pnpm_store" != "" ]; then
   pnpm_home="$(dirname "$host_pnpm_store")"
   run_args+=(
@@ -46,6 +51,7 @@ if [ "$host_pnpm_store" != "" ]; then
   )
 fi
 
+# Share the PDM cache with the container, if it's available locally
 if [ "$(pdm config install.cache)" == "True" ]; then
   host_pdm_cache="$(pdm config cache_dir)"
   run_args+=(